The present invention is directed to an underhood lamp assembly having a gravity-actuated switch for selectively supplying power to an underhood lamp.
Gravity-actuated switches have been used in the past to supply power to a lamp provided beneath the hood of an automobile to illuminate the engine when the hood is raised. When the hood is lowered, the gravity-actuated switch disconnects the lamp from the power source. Such switches have also been used on the trunk lid of an automobile.
Various types of gravity-actuated switches have been previously devised. For example, one conventional type of gravity-actuated switch, known as a mercury switch, contains elemental mercury which in its natural liquid state flows under the influence of gravity to selectively interconnect a pair of electrical contacts. Although their operation is generally satisfactory, mercury switches have the disadvantage that they contain mercury, which may cause harm when exposed to the environment.
Another disadvantage of gravity-actuated switches is that the load current which is used to supply electrical power to activate a power-consuming device is typically passed through the switch itself. As a result, electrical contact arcing may occur across the contacts of the switch, thus shortening the operating life of the switch and generating undesirable electromagnetic interference.